Jan, of Durham, N.C., writes: "I would like a word to describe the tire fragments left by the roadside when a truck tire blows. I commute on a busy highway, and there is always some debris in the road or on the shoulder."

In response to the question from Jan from Durham, N.C., concerning "a word to describe the tire fragments left by the roadside when a truck tire blows," this word suddenly came to me as I was driving down a highway:
"extirement" (ek' stir ment) -- similar to excrement, which describes all the mess left from blown truck tires on the shoulder ("Somebody should come out here and clean up all this %#@$!"). What do you think?

"FACT: Rubber on the road comes from both new tires and retreaded tires, primarily from truck tires that are overloaded, under inflated, or otherwise abused. New or retreaded tire failures can be greatly reduced by following all the rules of good maintenance, including proper mating with regard to diameter and tread depth and design, as well as maintaining proper air pressure."

Sure "rubber on the road" is less concise than Jan's "tire fragments", but now we know how they got there and what can be done about the problem.

I think I found the answer. There is a site called Tire terminology at http://www.intlscience.com/TranslatorsCorner/TireTerminology.html, which lists the following definitions:
"Chipping"; loss of small pieces of tire due to rough terrain (e.g. offroad).
"Chunking"; loss of large pieces of tire due to centrifugal forces created at high speed running.

So the big ones are chunks and the little ones are chips.

But I still have one question: Is this what was meant by "Don't tread on me?"

Scattermoth's Modern Dictionary has the word "rubberish" and the definition pointedly refers to exactly what you describe: n. rubberish: the debris left on the edges of the berm or sometimes in the center of the road after a truck tire blows"

In their passing, tires deposit microscopic particles of rubber on the road. Each particle is a new larval tire. From the moment of birth, the tiny proto-tires instinctively migrate to the nearest road shoulder. They join others on the way to form small colonies, and then larger clusters, that appear to speeding observers as chips, shreds, curls and treads. The last stage happens only on the darkest nights, when the treads undergo a convulsive involution and emerge as mature tires. After midnight under the new moon, the tire harvesters cruise the roadways and load their trucks.

When I was young, before everything was made from synthetics, we heard stories; stories about undomesticated tires living in the woods near the highway. We had seen them ourselves, resting in muddy sties and dangling like monkeys in trees.

According to legend, rubber is alive. As old cars rolled down the road, they deposited microscopic particles of rubber on the pavement. Each particle is a larva, each tire a parent. At the moment of birth, the tiny prototires instinctively migrate toward the shoulder of the road. They join others along the way forming thin processions that in the scale of the old west would be like a wagon train a thousand miles long.

When they reach the shoulder they form small colonies. As more protos arrive they become larger clusters. When large enough, they become the clutter that motorists observe as they speed by. The last stage happens only on the night of the new moon, when the treads undergo a convulsive involution and emerge as mature tires.

Life for an undomesticated tire is tough. Those that make it to the edge of the road and adulthood face further challenges to their survival in the wild. After midnight on the darkest nights, tire harvesters cruise the roadways and load their trucks.

There is an advantage to their isolation in the woods near the highway. It's key to their survival. No humans live there. Most people don't go there except for the occasional moment or two of relief. That's why undomesticated tires go mostly unnoticed, why modern science hasn't written about them, and why great journalists don't comment on their social and economic plight. People notice them sometimes. But they don't really see them, if you know what I mean.

At first we took the stories for just what they seemed to be, just stories. It was entertaining to hear the theory of their birth as their parent tires rolled by. We thought little of it when we first heard of it, like the strange ramblings of UFO sightings and ghost stories.

But WE decided to test the theory. That led to the first of what is now our traditional Sunday drive. The three of us, now four, scouted the highway looking for ripe clusters. Being novices our first time out, we began three weeks before the new moon hoping to find the best spot. John was a fisherman and lectured endlessly about the effects that temperature, instinct, and even rain might have.

We discussed the possibility of danger and then chuckled it away. "Have you ever heard of anyone being mauled by a freshly constituted clan of retreads?" I've tried to remember who said that first, but always come up thinking it was a joint effort, something that emerged from the loose clutter of our excited chitchat.

After about two weeks of intensive searching and note taking, Mary declared a clear winner. Out on interstate 95 a group of clusters had formed that reminded us of a grand community of fire ants. Surely, we thought, each hill would produce a bicycle tire. The site also had the advantage of being next to an open field. We made plans to sit in the car with sandwiches and maybe a little Lone Star beer. "A real night of it," we said.

We wanted it all to go perfectly and so started the evening working down a checklist. Food - check. Beer - check. Ice - stop at the convenience store on the way. We headed out for a last look at the site, to make sure that our colony had not been ravaged by war or met some other untimely fate. We were surprised beyond all earlier expectations. Soon into our trip we spotted a new colony, with black rolling hills and valleys that contained enough tread for a whole sixteen-wheeler.

Mary got all excited. She kept telling me to stop and turn around so we could inspect the mounds. She sounded frustrated with me as I continued driving, eyes fixed forward like I didn't hear her. I saw something about a hundred yards ahead. About half way Mary saw it too. Then John said, "Geeeezzowie!" There was another great mass of chips, shreds, curls and treads about twice the size of the last one.

A hundred feet ahead came a third dark rolling mass. This third colony tapered off to thin low trails meandering through isolated villages, then shot up again into massive towers. Mounds of varying proportion began appearing on both sides of the road with trails between each forming a continuous chain of bustling cities.

We drove on, dazed. The mass on the right side of the road faded again continuing in a smooth thin trail, not ending until it climbed to a gargantuan metropolis where our ant hills once stood. The new moon would appear that night. Like the shores of ancient China, Greece, and Egypt, the edge of the road had become the birthplace of a great civilization.

What this meant and how it had come to be in such a short period of time was boggling my imagination. I needed to collect my thoughts.

In Texas, people have long since forgotten the ancient celebrations of the seasons, having found no reason to celebrate midsummer especially. It's warm most of the year, when it's not hot. Better to rouse a sleepy air-conditioned bar or relax in the shade with an ice-cold glass of tea than to embrace the weather with any ritual.

"Frogs …," John choked. Mary and I looked for frogs on the highway but saw none. We looked at John again and then at each other. He knew about midsummer's eve because of his knowledge of fishing and frogs. That didn't matter, or so we thought.

We looked back at John again. He held his face in his hands. Mary and I began making serious plans. We no longer needed to concern ourselves with where the high mounds stood. They were all around us.

The best plan, we decided, was to park the car and hide in the woods behind one of the communities, somewhere we wouldn't be detected. We decided to stick to the old plan when it came to sandwiches and beer, except for the ice. We'd have to start out with cold ones after dark.

John never said another word, except once. He was staring down at his shoes, red-faced, shaking his head and pulling his hair. "Frogs," he said. And then again, "Frogs."

The woods behind the great metropolis turned out to be right for our purposes. We could sneak in over the thin trail leading up to it with cover from some nearby bushes. So that was the plan. As we saw the last orange glow of sunset we assembled the sandwiches and beer and made our way across, hauling John along by his hand.

We found the perfect spot for sitting up next to a small group of trees. We scouted the area stealthily, Mary and I speaking in whispers and hand signals. There were more bushes between us and the city but we could see around them when we wanted to. That was good. Mary pointed and snickered, "The Great Mounds of Roador." We lost control and chuckled a bit too loudly, then both sounded "sshhh!" at the same time and broke up chuckling again. It helped ease the tension.

The location secured, we turned our attention to the sandwiches and Lone Star beer. John was sitting quietly near the bushes, staring intently in the wrong direction.

We took our duties very seriously at first, somehow imagining that we knew what they were. We tested our skills as sentinels, each sneaking a peak and darting back for cover again. The moon was bright and the sky clear. We began mapping the features of the mounds for later comparison, only twice pointing out shadows and correcting ourselves.

Late into the second beer, I sat back and relaxed a bit. I shook my head while pealing the label from the bottle. "The Great Mounds of Roador," I mused. Mary smiled back, encouraging the light chatter.

I pitched my voice higher and became a little sing-songy. "Road decor, in the great tradition of Marshall McLuhan," I said.

We were on a roll and I fired back with my best imitation of Johnny Carson. "Interstate ennui."

A question shot across Mary's face. I shrugged my shoulders.

She then sounded rather philosophical. "If there's rubber on the road, did the blown tire make a sound?"

By then I felt forced to go on. "Is a tire only the afterburn of the wheel?"

With that, we each took another Lone Star, tipped them in quick salute, and drank. Each swallow took us deeper into the philosophical ramifications of rubber. Around our fourth bottle (each), we were convinced that the situation was of enormous importance to the future of humanity. It was on that account that we began to formulate a daring plan.

Douglas Adams? Probably not. I'm pretty sure I thought this one up all by myself. But, you know, one comes across so many ideas -- original, derivative, second-hand, third-hand -- and they all go into the hopper...

When I was in high school, my local favorite rock band, Blotto, who were known for their humorous lyrics, did a parody "metal ballad" that included the line "...my heart is in your hands," always followed by a pause, grimaces of disgust by all the band members, and, sotto voce, "ewwwww" and "yuuuuch."

Now if that band could only sing the tire story and react to the lyrics appropriately. I see a whole Broadway show coming out this. Title? "Treads" Think of all the highway driving songs...never mind the show would be ten hours long.

This may be a little too regional but in Louisiana and Texas a common "road-killed" animal is the armadillo. For that reason, we have decided to call dead tire fragments "tiremadillos". We have come to believe that these shy creatures, which have never been successfully photographed alive, are often hit by passing vehicles as they try crossing the hiway.

Actually, armadilloes are killed when they are in the middle of the road. They jump when they get startled by the approaching vehicle. So, they get hit by the front bumper or grill. I read that somewhere. Hmmmmm . . . can't seem to remember. Also, they always have identical quadruplets. I am a wealth of useless knowledge.

I was also thinking along the lines of flotsam and jetsam... Since the pieces of tire come from large "MOTor" vehicles, why not coin the term "motsam"? Seems to capture the spirit of what you're seeking.